Transcript Conjugate Acid-Base Pairs - Woodland Hills School District

Conjugate Acid-Base Pairs
Acid Dissociation
+
H
1-
HCl
Cl
Acid
Conjugate base
Conjugate pair
Kelter, Carr, Scott, Chemistry A World of Choices 1999, page 280
Conjugate Acid-Base Pairs
conjugates
HCl
+
base
acid
H2O
H3O+
+
acid
Clbase
conjugates
HCl
acid
+
H 2O
H3O+
base
CA
+
ClCB
Conjugate Acid-Base Pairs
conjugates
acid
NH3
+
H2O
base
base
NH41+
+
OH-
acid
conjugates
NH3
base
+
H2O
acid
NH41+
CA
+ OHCB
Water is Amphoteric
Amphoteric or Amphiprotic substances:
Substances which can act as either proton donors (acids) or
proton acceptors (bases) depending on what substances are present.
HCl
+
acid
NH3
base
+
H 2O
H3O+
base
CA
H2O
acid
NH41+
CA
+
ClCB
+ OHCB
Amphoteric
A substance that can act as either an acid or a base.
11+
+
H3O+
hydronium ion
+
HSO4hydrogen sulfate
ion
1-
H2O
water
H2SO4
sulfuric acid
2-
1-
+
HSO4hydrogen sulfate
ion
OHhydroxide ion
+
SO42-
H2O
sulfate ion
water
Amphoteric
A substance that can act as either an acid or a base.
11+
+
H3O+
hydronium ion
+
HSO4hydrogen sulfate
ion
(HSO4- as a base)
H2SO4
sulfuric acid
H2O
water
Amphoteric
A substance that can act as either an acid or a base.
1-
21-
+
+
HSO4-
OH-
SO42-
H2O
hydrogen sulfate
ion
hydroxide ion
sulfate ion
water
(HSO4- as an acid)
Conjugate Acid-Base Pairs
conjugates
base2
HC2H3O2 + H2O
acid2
H3O1+
+
acid1
C2H3O2OHbase1
conjugates
HC2H3O2 + H2O
acid
base
H3O1+
CA
+
C2H3O2OHCB
The reaction proceeds in the direction such that the stronger acid
donates its proton to the stronger base.